1. Technical Field
Example embodiments of the present invention relate in general to support of machine type communication (MTC), and more particularly, to an MTC support method and apparatus capable of providing efficient MTC user equipment (UE) service in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE)-based mobile communication system.
2. Related Art
MTC or machine-to-machine (M2M) communication is a form of data communication which involves one or more entities that do not necessarily require human interaction.
Service optimized for MTC differs from service optimized for human-to-human (H2H) communication. In comparison with current mobile network communication service, service optimized for MTC can be characterized by a) several market scenarios, b) data communications, c) lower cost and less effort, d) a much larger number of communicating stations, e) a wider service area, f) very low traffic per station, and so on.
MTC may appear in a variety of service forms, such as smart metering, tracking and tracing, remote maintenance and control, and eHealth.
In current 3GPP, MTC standardization is under way using the term “machine-to-machine (M2M) communication.”
In the present invention, a station that supports LTE or LTE-Advanced conforming to the 3GPP standard Rel-Aug. 9, 2010 is referred to as a legacy LTE station to be distinguished from MTC UE discussed in the present invention.
In Rel-Aug. 9, 2010, legacy LTE stations are defined to support a transmission/reception bandwidth of up to 20 MHz. MTC UE is intended for low cost and support of a low transmission rate, and thus can have a smaller bandwidth than a system bandwidth of a base station.
In Rel-Aug. 9, 2010, a physical broadcast channel (PBCH) through which synchronization signals, that is, a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and system information are transmitted, is transmitted with a bandwidth of 1.08 MHz with reference to a center frequency of a system bandwidth.
Here, 1.08 MHz is the same as a bandwidth obtained by excluding guard bands on both sides from 1.4 MHz that is the minimum system bandwidth. Thus, MTC UE can receive a PSS/SSS/PBCH even in a narrower bandwidth than a system bandwidth of a base station.
However, since a legacy physical downlink control channel (PDCCH) that is a control channel, a physical control format indicator channel (PCFICH) through which the number of orthogonal frequency division multiplexing (OFDM) symbols occupied by the legacy PDCCH is transmitted, and a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) through which ACK/NACK information about a physical uplink shared channel (PUSCH) is transmitted, are transmitted over an entire system bandwidth, MTC UE that has a narrower bandwidth than a system bandwidth of a base station cannot accurately receive these channels.